Add yield generator to python function

Question

I have this problem statement:

For optimal performance, records should be processed in batches. Create a generator function "batched" that will yield batches of 1000 records at a time and can be used as follows:

  for subrange, batch in batched(records, size=1000):
      print("Processing records %d-%d" %(subrange[0], subrange[-1]))
      process(batch)

I have tried like this:

def myfunc(batched):
    for subrange, batch in batched(records, size=1000):
        print("Processing records %d-%d" %
        (subrange[0], subrange[-1]))
     yield(batched)

But I'm not sure, since I'm new into python generators, this simply doesn't show anything on the console, no error, nothing, any ideas?

have you read anything about generators? For example the first google result wiki.python.org/moin/Generators — user8408080
– user8408080, Commented Dec 16, 2018 at 19:08
Your homework assignment says you are supposed to "Create a generator function "batched" …" not call batched like you are doing. — Red Cricket
– Red Cricket, Commented Dec 16, 2018 at 19:10

Aaron_ab · Accepted Answer · 2018-12-17 08:05:17Z

2

Generators are lazy, should consume or bootstrap it in order it to do something.

See example:

def g():
    print('hello world')
    yield 3

x = g() # nothing is printed. Magic..

Should either do:

x = g()
x.send(None) # now will print

Or:

x = g()
x.next()

[edit]

Notice that when doing .next() explicitly, eventually you'll get StopIteration error, so you should catch it or suppress it

edited Dec 17, 2018 at 8:05

answered Dec 16, 2018 at 19:35

Aaron_ab

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1 Comment

NeoVe Over a year ago

Thank You very much

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